Such an assertion probably only startles you if you are a transportation planner. To most people it is common sense, but when is the last time you saw your city adding roads to reduce congestion?
You've probably seen all the recent news reports on the 2005 Urban Mobility Study telling us how bad congestion is and how much time we spend stuck in traffic.
Less attention is paid to the part of the report that discusses the cities that saw the least congestion. Most interesting is that cities that build roads to keep up with travel demand did not experience the congestion growth other cities did! A three page summary of that result is here. Especially check out the graph on p.3.
The crime is that only 4 cities built enough roads to be in that category--Pittsburgh, New Orleans, Tulsa and Anchorage.
It's time metro area leaders get serious about adding capacity to relieve congestion. New roads or expanding existing roads, we can build our way out of congestion. It ain't easy, but it can be done.